Microfluidic processes may use droplets as reaction vessels for performing chemical or biological reactions. In such processes, often referred to as droplet microfluidics, the required reagents must be encapsulated in the droplets and processed by microfluidic devices as needed for the reaction to take place. In many applications, several volumes must be combined in a specific sequence. Existing methods attempt to achieve this result by separately emulsifying a plurality of volumes, interdigitating droplets, and bringing the droplets into contact such that the droplets may coalesce to combine the volumes. However, while droplet coalescence has been demonstrated for pairs of droplets, the process is difficult to control and does not work reliably.
Injection is a microfluidic process whereby a volume is introduced into a droplet by flowing it past a pressurized channel that is triggered to inject volume into the droplet using an electric field. One disadvantage of injection, however, is that it can only add one fluid at a time into a droplet. Thus, when additional volumes are required to be added into a droplet, additional picoinjectors must be used, each of which requires that the droplets be spaced periodically, and that the electrodes and other supporting components be fabricated on the microfluidic device. Hence, traditional microfluidic devices that employ injection are complex, inefficient spacewise and difficult to both operate and control.
Accordingly, there is a need for a system for performing injection of multiple substantially controlled volumes into or out of droplets that is streamlined, compact and easy to operate and control.
The present invention provides a system, method and kit for performing injection of multiple substantially controlled volumes into or out of droplets.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.